While we have seen our share of smartphone designs, nearly all of of them have one big touch screen on the front. But what if a smartphone could have two different displays on one case? Microsoft has apparently filed a patent that would create such a product. PatentBolt.com has posted up some images and details from the company's filing with the US Patent and Trademark Office.

The design would have a regular high-powered touch screen on the front of the smartphone, along with a low-powered screen on the back of the case. The rear screen could be used to display a variety of information. For example, it could become an eInk screen for people to read texts more clearly than on the front screen of a smartphone.

The low-powered rear screen could also be used purely as an atheistic feature. It could display images with limited animation that would serve as a kind of electronic skin that would make the smartphone look different than the norm. The patent says that the rear screen could even be molded into the case of the smartphone.

While Microsoft frequently files for patents that never turn up as actual products, the idea of a second rear display screen for a future smartphone sounds like one that could be made right now.